Rework type binding to allow for type awareness in iterators

UpsilonTests/GeneralTests/ForLoopTests.cs

@@ -1,4 +1,5 @@
 using Upsilon;
+using Upsilon.BaseTypes;
 using Upsilon.Evaluator;
 using Xunit;
 
@@ -98,5 +99,21 @@ return value
             var actual = Executor.EvaluateScript<long>(input, Options);
             Assert.Equal(6, actual);
         }
+
+        [Fact]
+        public void GenericForLoopValueTypeBindTest()
+        {
+            const string input = @"
+arr = {100, 56, 28}
+for key, val in ipairs(arr) do
+    a = val
+    break
+end
+";
+            var script = Executor.ParseInputAndEvaluate(input, Options);
+            Assert.True(script.Bind().Scope.TryGetVariable("a", true, out var variable));
+            Assert.Equal(Type.Number, variable.TypeContainer.Type);
+        }
+
     }
 }